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According to the MapLight.org data compiled by CREW, since the 112th Congress began and Bachus took the chairmanship of the Financial Services panel, he has voted 87 percent of the time in line with the interests of the industry his committee oversees, 10 percent more often than the average Republican.

On subsectors within the financial services industry such as "Securities and Investment," "Finance/Credit Companies" and "Commercial Banks," Bachus' votes were even further out of line with his party. For instance, Republicans on average voted 46 percent of the time in line with Finance/Credit Card companies. Bachus voted 64 percent of the time in line with that sector.

"Members universally tell us there is no connection between votes and campaign contributions," Sloan said. "The data really belies that."

In interviews, chairmen and ranking members vowed that their contributions had no connections to their decisions as lawmakers. But several described encountering questionable situations.

"All that data is available. I think it's very legitimate to ask the question," said Rep. Doc Hastings (R-Wash.), who is now the chairman of the Natural Resources Committee, received $152,000 from industries under the committee's purview, a 562 percent increase from the $23,000 those industries donated to him in the 1998 cycle.

"I have always prided myself on doing what I think is the right policy. And none of that changes" when people donate campaign funds, Hastings said.

"I'm gonna vote the same way if I got zero dollars. I agree with them. We're on the same side of these things, and that's why they give me money," Peterson said.

"I don't think my votes have changed since I became chairman," Bachus said, noting occasions he's voted against industry interests. "My votes are based on what I think is right for my constituents." But Bachus said he remembers "one occasion" he saw something "totally out of sorts" on the House floor.

"The only time I've ever thought that the money had probably a corrupting influence was during the Internet gambling bill when Jack Abramoff was representing Internet gambling," he said.

According to the plea agreement Abramoff reached with the Justice Department in 2006, Abramoff received assistance from Tony Rudy, deputy chief of staff to then-House Majority Whip Tom DeLay (R-Texas), in blocking the Internet gambling bill. In return, Abramoff allegedly steered $50,000 in 2000 and 2001 through a nonprofit group he was affiliated with to Rudy's wife.

McKeon pointed to his length of service, arguing that his well-known views are the reason industry groups support him with campaign donations. "Those people have known me a long time," he said.

McKeon recalled only one occasion, "years ago," in which a would-be donor suggested he would provide campaign funds in return for assistance on a judicial appointment. McKeon called the man's son, a friend, and said he "never wanted to speak to him again," McKeon said.

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March 13, 2015

Tom Williams/CQ Roll Call

Rep. Elijah Cummings, D-Md., right, hugs Harold Schaitberger, General President of the International Association of Fire Fighters, after the Congressman spoke at the IAFF's Legislative Conference General Session at the Hyatt Regency on Capitol Hill, March 9, 2015. The day featured addresses by members of Congress and Vice President Joe Biden.